Embedding electrodes in drill bits used in the recovery of hydrocarbons can provide many advantages for operators of drilling equipment. The embedment of electrodes can provide a data source upon which operators can rely to determine the physical characteristics of the wellbore during the drilling process.
In conventional drilling scenarios, a model is developed by engineers prior to drilling a wellbore. Data from pre-drilling investigations, i.e. seismic surveys, are placed into the computer modeling system to allow the overall drilling trajectory to be determined to maximize the economics of the well by minimizing the amount of drilling and maximizing the amount of wellbore in pay areas.
While having a drilling model helps to plan the well, operators must be able to accurately track the wellbore progress during the drilling process. Without a reference source to determine positioning of the wellbore, operators are forced to guess where the position of the drill bit by using rudimentary calculations of assumed angles and numbers of drill string pieces used. This creates a “zone of uncertainty” during the drilling process that can lead to loss of contact between the wellbore and the geological stratum which contains the hydrocarbons. During ever increasing and lengthening drilling projects, the zone of uncertainty grows such that the positioning of the wellbore can be merely a guess by operators. As drilling projects can be very time consuming and laborious, the costs of a drilling project may be very expensive. Limiting possible zones of uncertainty can yield to significant reductions in expenditures on such projects by maintaining a maximum amount of contact between the wellbore and the hydrocarbon bearing stratum.
Feedback of data from the wellbore drill bit can provide a wealth of information when the data is related to positioning information. Unfortunately, retaining such data is very difficult and in conventional systems impossible. Drill bits, for example, have very limited location for electrode or sensor placement as well as wire placement within the drill bit. During normal drilling operations, operators try to perform various evaluations using conventional apparatus. While these various conventional evaluations, such as resistivity analysis of the geological formation, may help operators reduce the zone of uncertainty, their relative position on the drill string limit their overall effectiveness. If data for the evaluations could be attained closer to the drill bit, the ultimate evaluations would minimize error. Optimally, if the evaluations could be performed at the drill bit itself, operators could minimize the overall uncertainty of the evaluation process and the evaluations relevancy to the drill bit. There is thus a need for a method and apparatus to aid drillers in providing data from the drill bit such that drillers can accurately position the wellbore and reduce the zone of uncertainty.